<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <script>
      // 1. str.startsWith()
      // 语法：startsWith(searchString, position)
      // 作用：判断是否以某个字符串开头
      // searchString:  要搜索的字符串
      // position    :  在str中开始搜索的位置，默认为0  可选
      // 返回值  true / false

      const str = "To be, or not to be, that is the question.";

      console.log(str.startsWith("To be")); // true
      console.log(str.startsWith("not to be")); // false
      console.log(str.startsWith("not to be", 10)); // true

      // 2. str.includes(substr[, pos])
      // 作用：判断一个字符串是否包含另一个子串   true / false
      const str2 = "To be, or not to be, that is the question.";

      console.log(str2.includes("not to be"));
    </script>
  </body>
</html>
